On 19 March 2021, British Prime Minister Boris Johnson, a Covid-19 survivor himself, obligingly bared his left arm for the camera at London’s St Thomas’s Hospital, where had been in intensive care the previous April. He was then injected with his first dose of the Oxford AstraZeneca vaccine, known to scientists as ChAdOx1 nCov-19 (AZD 1222) . Mr Johnson went on to remark during this photo opportunity that he “did not feel a thing” and also said “I cannot recommend it too highly”. Every little gesture counts, and Mr Johnson had just done his bit, joining the ranks of political leaders and celebrities all out to cajole the wider public to get vaccinated against Covid-19 without further delay.
This vaccine is the product of a collaboration between vaccinologists at Oxford University’s Jenner Institute and scientists at AstraZeneca, an Anglo-Swedish pharmaceutical and biopharmaceutical company headquartered in Cambridge and headed by Pascal Soriot, a French pharmaceutical executive and veterinarian by training. A global licensing agreement was signed by the two partners in April 2020. The UK government then stepped in the following month, contributing £65.5 million to the joint effort. The modified adenovirus-based vaccine is now being manufactured at several sites, within the UK and across Europe and Asia, and including the Serum Institute of India in Pune- the world’s largest supplier of vaccines. The multi-stage multi-site “distributed manufacturing” process begins with development of the active product at certain locations, followed by “fill and finish” elsewhere prior to distribution. This complex supply chain is inevitably subject to disruption. For example, production in India has been affected by restrictions under the Defence Production Act on American exports of cell culture media, chemicals and specialised equipment necessary for vaccine production.
The earliest published study of the efficacy of the Oxford University-Astra Zeneca vaccine appeared in The Lancet as a preprint in February 2021. An interim analysis of the results of Phase III trials involving 17,178 participants in Brazil, South Africa, and the UK, showed an overall efficacy of 70.4 percent. The efficacy was lower (62.1 per cent) in those receiving two doses of the vaccine spaced fourteen days apart, but higher (90 per cent) in a group given a low dose at first, due to administrative misunderstandings earlier in the trial, followed by a second standard dose.
On 30 December 2020, the UK Department of Health accepted the recommendations of the nation’s regulatory body, the Medicines and Healthcare products Regulatory Agency (MHRA), and authorised emergency use of the Oxford-AstraZeneca vaccine in adults. This made it the second vaccine to be approved in the UK, following Pfizer’s BioNTech. The government then secured access to 100 million doses, on behalf of the UK and its crown dependencies ad overseas territories. The rollout of vaccine began shortly thereafter, from 4 January 2021, with the first doses being administered at the Churchill Hospital in Oxford, the location of the Oxford Vaccine Group.
The vaccine was conditionally approved for use in all ages by the European Medicines Agency on 29 January 2021. But four days previously, the German newspaper Handelsblatt had already cast doubts on the vaccine, citing a figure of 8 per cent efficacy in over-65s. The suspension of vaccine rollout in South Africa on 7 February only added to the doubts: a study of two thousand people suggested that the vaccine offered only limited protection against mild to moderate disease caused by the B.1.351 South African variant of Covid-19. The rollout of the vaccine in Europe was hindered by conflicting recommendations. Some European countries initially restricted vaccination to those aged between 18 and 64, only for France and Germany to later decide that only over-65s were to receive the vaccine. Doubts over efficacy and contradictory advice even led to reports of vaccine refusal by people, not otherwise vaccine hesitant, who claimed to have lost confidence in this particular product. The diversity of opinions about the vaccine can be seen in the fact that although the WHO approved use in all adults on 10 February, the Oxford-AstraZeneca vaccine has yet to be approved by the Food and Drug Administration for unrestricted use in America.
Some unhappiness over a perception that the EU has been deprived of its ‘fair share’ of vaccines by a predatory UK has lead to threats of vaccine warfare in retaliation, including retaliatory blocks on the export of vaccine from the EU to the UK. While the EU’s procurement programme has proved to be sluggish and somewhat uncoordinated, supply chain disruptions have meant that delays in delivery of the promised supply of AstraZeneca vaccine have only added to the EU’s vaccine shortages. Although AstraZeneca had agreed, in June 2020, to supply the EU with 400 million doses of vaccine, the company has had difficulties with delivering on its commitments.
The latest concerns with the Oxford-AstraZeneca vaccine have arisen following reports of blood clots, known to professionals as thromboembolism, leading to the suspension of rollout in several risk-averse European countries, both within and outside of the EU. As of 8 March, there were reports of fifteen instances of deep vein thrombosis and twenty-two recipients with pulmonary embolism, out of a total of seventeen million vaccinated. There are particular worries over an extremely rare clotting disorder, known as cerebral venous sinus thrombosis, reported in twelve women and one man, all aged between 20 and 63. A causal link to vaccination remains unproven, and it seems that the numbers represent, or may even be less, than the numbers expected under normal circumstances in unvaccinated adults. However, while emphasizing the considerable benefits of vaccination, the MHRA is warning recipients of the Oxford-AstraZeneca vaccine to seek medical attention if they develop headache that lasts for more than four days following vaccination.
The Oxford AstraZeneca vaccine has, unfortunately, become embroiled in a form of no-holds-barred “vaccine nationalism” At a time when we should be immunizing as many adults as possible and as soon as possible, priorities are being distorted by the politics of vaccination, complicated by doses of exuberant nationalism. It cannot be overstated that it is most important for everyone to follow the advice of the relevant national public health regulatory agencies, safe in the belief that public health officials are acting in the best interests of citizens. There is a lot yet to be said about Covid-19 vaccination and it is far too early to jump to conclusions that are not supported by the available information. .
Ashis Banerjee